Reenforcement



Aug. 17, 1926. 1,596,669

E. LIGON NET REENFORCEMENT Filed Dec. 5, 1924 Fig.2

Patented Aug. 17, 1926.

ITED STATES EUGENE LIGON NET, OF PARIS, FRANCE.

REENFORCEJNTENT,

Application filed December 5, 1924, Serial No. 754,174,

T his invention relates to helically-wound wire reenforcements, applicable more particularly to drain-pipes and other cylindri-V cal or cylindro-co1ncal articles made of re- 5 enforced cement, baked earthenware, rubber or other materials and produced by centrifugation or casting with the aid of compressed air orby other means; the invention presenting improvements upon reen- 1 forcements of this type wherein the adjacent convolutions of the main or circumferential helically-wound element of the reenforce ment are secured at the required distance apart by their engagement between the adjaccnt com'olutions of a plurality of spacing-members in the form of continuous wire helices of relatively small diameter each of which is held in position by means of a rod extending through it longitudinally.

In a wire reenforcement in the form of a grid for use in the construction of concrete roads, floors, walls and such like structures,

and comprising layers of rods crossing one another at relatively wide intervals it has C the several rods of one layer toa rodof the other layer, to provide a spacing-member constituted by a wire extending alongside of said rod of the second layer and presenting. at intervals corresponding with the spacing of the rods of the first'layer, as many isolated sets of spiral bends; each rod of said first layer being received and gripped between adjacent convolutions of the corresponding set of spiral bends of the spacingmember, whilst what may be termed a locking-wire is passed through all the sets of spiral bends on tll" spacing-member so as to retain within them the rods of the first layer; there being as many of such spacingmen'ibers as there are rods of the second layer, so that the rods of the respective layers held together at each crossing-point. According to the present invention, which is applicable only to helically-wound rcen forcements having continuously-wound spacing-members, two longitudinal rods are employed in combination with each spacingmcinber, the one rod extending inside and the other outside the main or circumferential helically-wonnd element, hereinafter referred to as the directrix; said longitudinal rods being placed opposite to one another 'ameter of the continuous helix,

upon that d1 constituting the spacing-member, which is 5 been proposed, for the purpose of attaching and in France December 12, 1923.

substantially coincident with that radius of the main or circumferential element which intersects the axis of said helix; and the conjoint thickness of the wires constituting the main or circumferential element and the inner and outer longitudinal rods being substantially equal to the internal diameter of the helical spacing-member so as, by fitting therein, to lock the spacing-member securely in position. I

The spacing-members received in recesses on the periphery of the mandrel. Each inner longitudinal rod, which may have its outensurface substantially flush with the outer surface of the mandrel, is hereinafter for convenience referred to as a generatrix; Whereas each outer longitudinal rod is referred to as a locking-pin.

In addition to'the various elements men tioncd above, there may be employed one or more wires which"are wound, as helices oi are temporarily steep pitch, externally of the directriX and in a direction contrary thereto, so as to prevent any tendency to distortion as a whole whenfreed from the support of the mandrel.

In the accompanying drawings Whichillustrate a typical embodiment of the invention, Figure 1 is aside elevation of the improved reenforcement, and Figure 2 is a cross section thereof, shown as mounted on a mandrel for purposes of assembling.

Into each helix (2 constituting a spacingmember is inserted a straight rod of steel or other metal, which constitutes a generatrix and is of the same length as the helix. As many gencratrices Z) (provided with spacing-members a) as may be desired are arranged around a mandrel 0 of any collapsible type. At the points corresponding to the positions of the generatrices b, the mandrel is provided with recesses (Z, of the same shape as the. helices a and of a depth which is determined by the gauge of the wireof the helix a. and of the generatrix Z). The ge eratrices b and helices a. may be tempo a'rily held position in the recessesd of the mandrel by any convenient fasten inn means.

The directrix e is wound on the mandrel and over the generatrices Z) in the opposite direction to the Winding of the helices a, and in such a way that its convolutions will come exactly into position between the conof the structure.

volutions of said helices, so that the latter act as spacing-members for the convolutions of the directrix, the elasticity of the two windings operating in opposite directions.

When the desired length of dtrectrix vehas been wound, each of its ends is secured by tying or soldering, and the generatrices b are turned back over the last tHI'HSOi the directrix 0, so as togrip them in the manner between the generatrix b and the lockingpin f,(see Figure 2).' g y I In addition; itis advisable to wind upon the exterior 'ofthe reenforcement a wire g, intheform' of a helix of steep -pitch,'in

a direction'oppositeto that of the winding of the directrix e. This'wire g is also hooked at the ends. Its object is to prevent distortion of the reenforcement as a whole, or torsional movements of ,the 'directrix after separation from the mandrel. V

Each helix 0 may be of cylindrical, oval, square or other shape in'end yiew,'its sectional dimensions being d'eterminedby those "of the bar "b, direetrix e and locking-pin f,

whilst the pitch of each helix a isdetermined by the sectional dimensions of the directrix e and by the number of convolutions of the latter per unit oflength.

The in'iproved reenforcement is applicable "not'only to pipes, but also to posts or similarflarticles, and it permits of any commercial kinds "of steel being used, whatever their strength.

The directrix may be wound by hand, or preferably on -a;1nachi-ne by the aid of a leading-screw which gives a suitable pitch.

What I claim is i 1. A wire reenforcement for cement pipes comprising in combination a helically-wound main element a plurality of helically-woun-d spacing members, the convolutions of saic spacing members being spaced apart a distance equal to the distance between the convolutions ofth'e main element, and two longitudinal rods'within each of said spacing members, one of said rods beingon the inside and the other on the outside of said main element. 7

' 2. A wire reenforcement for cement pipes comprising in combination aJhelically-wound main element, a plurality ofhelically-wound spacing'members, theconvolutions of said spacing members beingspaced apart a dista'nee equal to the distance between the convolutions of the main element, two longitudinal rods within each of said spacing members, one of said rods being on the inside and the other on the outside of said main element, and a plurality of helical members of steep pitch' wound upon said main element.

In testimony whereof I hereunto afiix signature.

EUGENE LIGONNET. 

